Process for preserving citrus fruit food products

ABSTRACT

PRESERVATION OF PEELED AND SECTIONALIZED CIRTUS FRUITS BY COOKING THE FRUIT IN A CLOSED, PARTIALLY VACUUMIZED GLASS CONTAINER AT GAUGE PRESSURES OF BETWEEN (5 AND15) 2 AND 20 P.S.I. AND AT TEMPERATUTES BETWEEN (225*F. AND 250*F.) 219*F. WITH SUBSEQUENT COOLING OF

May 29, 1973 H. COHEN PROCESS FOR PRESERVING CITRUS FRUIT FOOD PRODUCTSOriginal Filed July 10. 1964 SCALDER PEELING LYE PEELI NG EXHAUST BOXCOOLER BLOWER FILLING MASTER CARTONS STORAGE Herman Cohen INVENTORTTORNEYS United States Patent Ofice Re. 27,646 Reissued May 29, 1973Int. Cl. A23!) 7/00 US. Cl. 99-186 4 Claims Matter enclosed in heavybrackets appears in the original patent hut forms no part of thisreissue specification; matter printed in italics indicates the additionsmade by reissue.

ABSTRACT OF THE DISCLOSURE Preservation of peeled and sectionalizedcitrus fruits by cooking the fruit in a closed, partially vacuumizedglass container at gauge pressures of between [5 and 2 and psi. and attemperatures between [225 F. and 250 F] 219 F. and 259 F. withsubsequent cooling of the container and its contents.

This application is a continuation of Ser. No. 766,357, filed Aug. 27,1968, n w abandoned, which is an application for reissue of U .8. Pat.No. 3,396,040, Aug. 6, 1968, which in turn is a continuation-impart 0;Ser. No. 348,489, filed Mar. 2, 1964, now abandoned.

[This application is a continuation-in-part of my copending applicationentitled Process for Preserving Citrus Fruit Food Products, filed Mar.2, 1964, and assigned Serial Number 348,849 now abandoned] The presentinvention relates to the processing of containerized citrus products.

In the continuous or batch type processing of sectionized fruit it hasheretofore been the practice to process such fruits in tin cans bycooking the fruit at predetermined temperatures usually below theboiling point of water for varying periods of time between to 40minutes, the actual times and temperatures depending on the type andmaturity of the fruit which was being processed. Such processingoperations, however, were found to bring about a tinny flavor in theprocessed fruit as well as rendering the same undesirably soft due tothe long period of cooking. The tinny flavor was found to become moreprofound as the period of storage was prolonged. The fruit furtherbecame discolored after minimal periods of storage in the tin cans andcontinued to take on a more brownish color as storage time wasprolonged.

Due to the undesirable properties of the fruit sections which wereprocessed in the above described manner, and with the advent ofrefrigeration, the food processors in the citrus fruit industryattempted to eliminate the disadvantages and drawbacks of the priorprocess. These processors turned to refrigeration to preserve the citrusfruit in a more desirable manner. The tinny flavor was eliminated aswell as the discoloring of the fruit and the softness thereof. However,in order to obtain these more desirable results with the refrigerationprocess, the industry found that it was necessary to supplement thesyrup or citrus fruit juices which the fruit sections were stored in,with benzoate of soda. Approximately one tenth of 1% benzoate of sodawas added to the syrup or fruit juices in order to prevent deteriorationof the citrus sections upon prolonged storage. As a result of suchsupplementation, it was found that the fruit when eaten created a slightburning sensation to the tongue. As a further drawback to this process,it was found that the cost of refrigeration was exceedingly high. Thishigh cost was brought about by the fact that it was necessary tocontinually refrigerate the containers and the contents thereof from thetime of processing until the time at which the fruit sections werepurchased by the consumer. Thus, it was further necessary to refrigerateany transportation vehicles which carried the processed fruit sections.

In view of the preceding discussion of past and present methods ofoperation in the fruit processing industry, it is a primary object ofthe present invention to provide a dependable and efficient method ofprocessing fruit sections wherein the objections to the presently knownmethods as well as the objections to the methods previously used, areavoided.

It is another primary object of the present invention to provides aprocess of preserving citrus fruit sections in such a manner so as toretain the natural flavor of the fresh fruit as well as the stability orfirmness of the fruit sections and to maintain the original color of thefruit after prolonged periods of storage.

Still another and further object of the present invention is to providea process for preserving citrus fruit sections in containers which aresealed so as to provide a partial vacuum condition within the containersduring the period of storage. In line with this object of the presentinvention, it is a further object of the present invention to partiallyfill the containers with fruit sections to a predetermined level andmaintain the same in a solution such as syrup and/or citrus fruit juicesfor preserving the fruit sections in a manner which results in anacceptable fruit condition when purchased by the consumer.

Another object of the present invention is to provide a reliable processto preserve citrus fruit sections such as oranges, grapefruits andcombinations thereof by cooking the same in containers at predeterminedtemperatures and pressures for predetermined periods of time. Inconnection with the preceding object of the present invention, it is afurther object of the invention to cool the containers and the contentstherein as rapidly as possible to approximately room temperature forstoring the same and shipping to the commercial outlet.

Still another further object of the present invention is to provide aprocess for preserving citrus fruit sections such as previouslydescribed, which process includes the use of containers comprising aglass composition or other materials having similar characteristics andproperties which are capable of withstanding heat, cooling and othersuch operations connected with the present process, rather than tin cansor other known receptacles presently used in the fruit processingindustry.

Consistent with the preceding basic and elementary objects of thepresent invention, there are certain other objects hereof including thefollowing:

(a) The provision of such a process wherein the basic sequential stepsperformed include a preliminary scalding of the various fruits to bepreserved an initial peeling of the outer skin from the fruits, a lyepeeling to substantially remove all covering from the fruit,sectionizing and filling of the fruit sections into suitable containers,exhausting substantially all air from the unfilled portions of thecontainers, cooking the fruit sections under pressure and then coolingthe containers and the contents therein;

(b) The provision of such a process wherein the respective operationalsteps are carried out in a sequence where certain operations in thesequence are carried out at predetermined ranges of temperature andpressure and for pre-selected periods of time;

(c) The provision of such a process which utilizes a particular densityof syrup capable of effectively maintaining the fruit sections at adesired degree of firmness, similar to freshly sectionized citrus, andmaintaining the color of the fruit sections as close to the normal colorof fresh citrus fruit as possible, and to further maintain the desiredtaste of the fresh citrus fruit sections; and

(d) The provision of such a process which can be carried out efficientlyin a continuous or batch type operation and in such a manner as tominimize operational costs.

In the process of the present invention, the citrus fruit products arefirst treated in such a manner as to allow for rapid and efficientpeeling of the skin from the surface of the citrus fruit. Such treatmentusually includes scalding of the citrus fruit wherein sufficiently hightemperatures and resultant heat are applied thereto so that peeling ofthe skin therefrom, either manually or by automatic means, can bereadily accomplished.

It is desirable to pass the fruit through a peeling and lye peelingoperation that completely removes the outer skin or surface coveringfrom the fruits such as grapefruits, oranges, and the like, so that thefruit itself can be sectioned and placed in a suitable container. Aftersectionizing and filling of the various types of fruits in the desiredcontainers, the process contemplates either adding a syrup solution,citrus juice or combination of juice and syrup, to the partially filledcontainers or having the syrup or juice placed therein before thecontainers are filled with the sectionized fruit. The containers andcontents therein are then run through an exhaust box to heat thecontainer and contents forcing the air in the container to expand whichwill create a vacuum upon being cooled. A suitable closure is thenplaced on the individual containers so as to maintain the partial vacuumtherein. In order to maintain the desired taste, color and stability ofthe fruit sections, the same are cooked under pressure in a retort orother desired receptacle for a predetermined period of time and at adesired range of pressures and temperatures. After such cooking, thecontainers are removed from the retort or other type of cookingreceptacle and then cooled by air blowing water spray, or otherconventional cooling techniques until a desired cooling temperature isreached.

The invention resides in a particular sequence of operations, in themanner in which such operations are performed, and in the particularranges of temperature, pressure, and periods of time for carrying outcertain operations in the overall sequence. The invention will be betterunderstood and objects other than those specifically set forth abovewill become apparent, when consideration is given to the followingdetailed description. Such description makes reference to the annexeddrawing.

The single figure of the drawing is a diagrammatic view showing theessential steps in the preferred process of preserving citrus fruitsections.

By way of example, let it be assumed that grapefruits and oranges are tobe combined for ultimate sale to the consumer at some later time. Itshould be understood however, that any combination of fruits can beselected or individual fruits may be separately processed. The orangesand grapefruits are first scalded in a conventional manner such assubjecting the fruits to superheated steam or boiling water so that theouter skin of the grapefruits and oranges is suli'iciently prepared forthe peeling operation which will remove the outer skin from the fruits.Inasmuch as the peeling operation does not substantially remove all ofthe covering on the fruit itself, it is desirable to subject the same toa lye peeling operation wherein all of the outer surface of skin isremoved therefrom. The oranges and grapefruits are then cut orsectionalized into varying numbers and sizes of pieces depending on theinitial size of the grapefruits and oranges. This sectionalized fruit isthen placed in a container which can be of any selected size and whichcan either be initially partially filled with a syrup solution orsubsequently partially filled with the syrup solution after the jars arepartially filled with the fruit sections.

Consistent with the invention, the container used can take various formsand can be made of various dilferent materials. It has been found,however, that glass containcrs ca be p ocessed a co d g to the i ve tionquite efficiently. Still, containers made from synthetic materialsand/or metals can be processed according hereto without departing fromthe teachings hereof. In any event, the container should be capable ofwithstanding the temperatures, pressures, and other processingenvironment characteristics. For convenience, it is assumed in thefollowing discussion that glass containers are being utilized, but thisassumption is made subject to the understanding that plastic, metal orother types of containers can be employed.

Again referring to the invention itself, it should be noted that thecontainer or jar is only filled with fruit to approximately one quarterof an inch from the top thereof so that the jar when placed in theexhaust box may be exhausted of substantially all air in the unfilledportion of the jar, thereby creating a partial vacuum therein. It hasbeen found that the container usually requires approximately one eighthof its volume to be filled with the citrus juice or syrup so that thefruit will be covered by the syrup or juice when placed therein.Approximately one quarter of an inch at the uppermost portion of thecontainer is sufficient for the partial vacuum when a suitable closureis secured to the container.

Although the particular syrup which is used in connection with thepresent process is not critical nor determinative of the particularsequence of steps involved, it has been found that the syrup can be of adensity range determined merely by the degree of sweetness associatedwith the syrup. In this regard, the solution might have a density offrom 0 Brix to 55 Brix. When the Brix density is between 0 and 16 Brix,the solution would be classified as sweetened water. When the density ofthe solution is between 16 Brix and 18 Brix, it would be classified aslight syrup. When the density of the solution is 18 Brix and above, thesolution is classified as heavy syrup. The term Brix is a classificationof solution expressing the percentage by weight of pure sucrose ordextrose or combination of the two, to the percentage of weight ofwater. Such terminology is conventional in the food processing industryand accepted by the US. Department of Agriculture as set forth in thewell known so-called A.O.A.C. Book.

After the glass jars have been sealed by a suitable closure in theexhaust box, so that the partial vacuum condition in the unfilledportion of the jars is maintained, the same are transferred to acontinuous pressure cooker or retort cooker of the pressure type whereinthe contents of the glass jars are cooked for a predetermined period oftime. More particularly, the cooker is maintained under a pressure ofbetween 2 lbs. per square inch and 20 lbs. per square inch, butpreferably between 5 lbs. per square inch and 15 lbs. per square inch.While the desired range of pressure is maintained in the cooker, theglass jar and contents therein are subjected to a temperature in therange between [200 F. and 275 F.] 219 F. and 259 F. but preferablybetween 225 F. and 250 F. Both the desired range of pressure and thedesired range of temperature are maintained for a period of time between2 to 12 minutes depending on the particular fruits. which are containedin the glass jars and the sizes of the same.

Due to the above described sequence of steps, the citrus fruit sectionsretain their natural flavor of the fresh fruit as well as retaining thefirmness of the fresh fruit. Moreover, it has been found that thisparticular sequence of steps prevents very little change in color of thefruit if the same is kept in a relatively unit area. However, in thoseinstances where the glass jars are stored under bright light for a longperiod of time, there may be a very slight change in color.

The glass jars and the contents thereof are transferred from the cookerto a cooler wherein the glass jars are cooled down to a temperaturewhich is normally that of room temperature. The more rapid the cooling,the greater period of time for storage which is afforded thereby. Inconnections with this cooling operation, it has been found that a waterspray or a forced air cooling is sufficient to rapidly cool the glasscontainers.

The glass containers are removed from the cooling area after the samehave been sufficiently cooled and placed in the master cartons fortransportation to storage. It should be noted that the processingoperations may take place in a continuous or batch type operation. Inthose cases where a retort type pressure cooker is used, the process canvery well become a continuous one. In this case, automation comes intoplay in the transportation of the fruit and the containers from onesequential step to the other. However, a batch type operation can verywell be adapted to the process for preserving citrus friuts set forthabove.

It will be seen from the above, that by the process of the presentinvention the problems which have arisen in connection with presentprocessing practices such as the change in taste, color and stability offresh fruit have been eliminated.

After reading the foregoing detailed description of the process forpreserving citrus fruits hereof, it should be appreciated that theobjects set forth at the outset of the present specification have beensuccessfully achieved. Accordingly,

What I claim is:

1. In a process for preserving peeled and sectionalized citrus fruit ina glass container having such citrus fruit therein, including fillingthe container to a level below the top thereof, the improvementcomprising the steps of:

(a) partially filling said container with a syrup;

(b) placing said glass container and its contents in a vacuum chamber toestablish a partial vacuum in the unfilled portion of said container;

(c) while maintaining the partial vacuum in said container, closing thetop thereof with a suitable closure;

(d) placing the closed container under a pressure of between [5] 2pounds per square inch and [15] 20 pounds per square inch and whilemaintaining the pressure, cooking the same at a temperature of between[225 F. and 250 F] 219 F. and 259 F. for a period of time between 2 to12 minutes, and then (e) cooling said container and its contents to roomtemperature.

2. The process of claim 1, wherein step (a) is carried out with a syrupsolution having a density of between 0 degree Brix and 55 degrees Brixand wherein said syrup consists essentially of at least one ingredientselected from the group consisting of water, citrus juice, dextrose,sucrose and mixtures thereof.

3. The process of claim 1 wherein said fruit is selected from the groupconsisting of oranges, grapefruits, and mixtures thereof.

4. The process of claim 1 wherein said glass container is filled with asolution selected from the group consisting of syrup, citrus juices, andmixtures thereof.

References Cited The following references, cited by the Examiner, are ofrecord in the patented file of this patent or the original patent.

Cruess: Commercial Fruit and Vegetable Products, 1948, p. 81.

Cruess et al.: Home Canning. 1942, pp. 18-25. 42, 43.

The Canning Trade, a complete course in canning, 5th ed., May 1924, pp.37-48.

MORRIS O. WOLK, Primary Examiner S. B. DAVIS, Assistant Examiner

